1. Field of the Invention
This invention relates to a method for antigen-antibody reactions and a reagent therefor.
2. Description of the Prior Art
At the present time, many in vivo reactions attract much attention in their relations to antigen-antibody reactions, particularly in the field of medicine and hygienic sciences and they are analyzed and investigated with the intention of promoting health conditions, treating diseases and the like. In addition, regarding in vitro reactions, immunochemical investigation is made intensely on the basis of samples which reflect in vivo conditions and a part thereof is already put to practical use in routine medical tests. Typical assay methods known as highly sensitive assay systems include radioimmunoassay (RIA), latex agglutination assay with near infrared turbidimetry (LPIA), enzyme immunoassay (EIA), fluoroimmunoassay, and nephelometry utilizing light scattering. Heretofore many immunological reactions have been conducted wherein antigens or antibodies in samples are detected with a reagent comprising, in addition to the liquid phase, the carrier matrix such as biological carriers, e.g., erythrocytes or bacteria and latex particles of synthetic organic polymer carriers, which can be sensitized with an appropriate antibody or antigen.
Immunological reactions show high specificity in that a reaction occurs strictly and selectively, which is one of their outstanding features, and they are assessed as an important medical test method.
On the other hand, body fluids which reflect activities of in vivo conditions have a wide variety of compositions and physical properties. On this account, many immunological reactions could not entirely be freed from non-specific reactions which can be said to be side reactions independent of the antigen-antibody reaction. As a countermeasure against such non-specific reactions, in many cases, such procedure as the addition of kaolin or similar adsorbent or extraction has been employed in order to remove or neutralize the relevant non-specific factors. Though part of such treatments are effective, it is necessary to make a detailed examination on each antigen-antibody reaction and they involve many difficulties in their practical use.